Chrome Box EIM - Does it Retard Advance?

Posted By: rtman

Chrome Box EIM - Does it Retard Advance? - 05/02/12 06:33 PM

Like the Orange box does at 4000RPM?

And, does anyone have a schematic of both the Orange and Chrome boxes? It has become an unfunded engineering project at my work

And any reference to MSD will be ignored...except someone who has an MSD that fits the stock loom

Posted By: JohnRR

Re: Chrome Box EIM - Does it Retard Advance? - 05/02/12 08:20 PM

Posted By: rtman

Re: Chrome Box EIM - Does it Retard Advance? - 05/02/12 09:28 PM

But, JRR, its a simple question that I have to imagine someone has the answer to...

Posted By: JohnRR

Re: Chrome Box EIM - Does it Retard Advance? - 05/02/12 09:40 PM

The

was for your what you edited out ...

I'll pm the rest of my response not to derail your question.

Posted By: maximum entropy

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 12:44 AM

my orange and chrome boxes must be aberrations.

Posted By: Dunnuck Racing

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 12:51 AM

What do you want as far as a schematic? They are wired the same. Both boxes have the same dwell/spark retard.At least the two orange and one chrome that I have dyno tested with do.
Keith

Posted By: JohnRR

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:16 AM

Quote:

my orange and chrome boxes must be aberrations.

Care to expand on that ?

His orange box was on a chassis dyno last friday , connected to it and it showed the timing retard above 4000 rpm.

Keith are you saying the chrome box also pulls out timing above 4000 rpm ?

Posted By: Dunnuck Racing

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:32 AM

Mine does. Both boxes had identicle dwell and timing curves through 6500 rpm which is as high as I tested them.

Posted By: lewtot184

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:34 AM

from my experience with the ecu boxes most will reduce dwell some as the rpm increases. not sure if that will retard timing. the timing retard that i have experienced as rpm increased was mechanical related, not electrical.

Posted By: JohnRR

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:37 AM

Quote:

from my experience with the ecu boxes most will reduce dwell some as the rpm increases. not sure if that will retard timing. the timing retard that i have experienced as rpm increased was mechanical related, not electrical.

How would centrifugal force acting on the weights retard the timing ?

Posted By: lewtot184

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:40 AM

Quote:

Quote:

from my experience with the ecu boxes most will reduce dwell some as the rpm increases. not sure if that will retard timing. the timing retard that i have experienced as rpm increased was mechanical related, not electrical.

How would centrifugal force acting on the weights retard the timing ?

my problem wasn't ignition related. timing chain with a little cam walk.

Posted By: JohnRR

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:41 AM

Quote:

Quote:

Quote:

from my experience with the ecu boxes most will reduce dwell some as the rpm increases. not sure if that will retard timing. the timing retard that i have experienced as rpm increased was mechanical related, not electrical.

How would centrifugal force acting on the weights retard the timing ?

my problem wasn't ignition related. timing chain with a little cam walk.

Everything on the engine in question is brand spanking new .

Posted By: Dunnuck Racing

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:43 AM

Dwell ddirectly affects timing,.

Posted By: lewtot184

Re: Chrome Box EIM - Does it Retard Advance? - 05/03/12 02:51 AM

Quote:

Quote:

Quote:

Quote:

from my experience with the ecu boxes most will reduce dwell some as the rpm increases. not sure if that will retard timing. the timing retard that i have experienced as rpm increased was mechanical related, not electrical.

How would centrifugal force acting on the weights retard the timing ?

my problem wasn't ignition related. timing chain with a little cam walk.

Everything on the engine in question is brand spanking new .

my timing chain was brand spankin' new too. just relating an experience, believe what you want.

Posted By: forphorty

Re: Chrome Box EIM - Does it Retard Advance? - 05/04/12 01:30 AM

How much timing retard are we talking about here?

Posted By: rtman

Re: Chrome Box EIM - Does it Retard Advance? - 05/04/12 04:11 PM

about 10 degrees dropping off at 4000-4200rpm

Posted By: maximum entropy

Re: Chrome Box EIM - Does it Retard Advance? - 05/04/12 07:18 PM

Quote:

Dwell ddirectly affects timing,.

not if the dwell starts earlier. it can be manipulated electronically. i've checked several orange boxes, and one chrome box, to 6000 rpm- no sign of retardation (pardon the choice of words). they are all old boxes, though. i think my newest one is over ten years old. i think ballast resistor selection is important, too. iirc, there are two resistance values available? i have always used the higher resistance, and have had no ignition issues ever (aside from a ballast resistor failing at an extremely inopportune time).

Posted By: JohnRR

Re: Chrome Box EIM - Does it Retard Advance? - 05/04/12 07:25 PM

Quote:

Quote:

Dwell ddirectly affects timing,.

not if the dwell starts earlier. it can be manipulated electronically. i've checked several orange boxes, and one chrome box, to 6000 rpm- no sign of retardation (pardon the choice of words). they are all old boxes, though. i think my newest one is over ten years old. i think ballast resistor selection is important, too. iirc, there are two resistance values available? i have always used the higher resistance, and have had no ignition issues ever (aside from a ballast resistor failing at an extremely inopportune time).

In the other thread about this subject it is claimed that there was a change made to them in 2000. So if your boxes are older than that it doesn't help with this question/problem.

But thanks anyway.

Posted By: maximum entropy

Re: Chrome Box EIM - Does it Retard Advance? - 05/04/12 08:28 PM

Quote:

But thanks anyway.

you're welcome.

Posted By: scatpacktom

Re: Chrome Box EIM - Does it Retard Advance? - 05/05/12 02:57 PM

I have a Sun distributor machine. When I first got it I thought I wasn't using it properly or that there was something wrong with it. The timing would reach full advance at whatever rpm and then at high rpm it would loose a few degrees at max rpm. Talking with other distributor machine owners, they have found the same trends. I'd still like to hear a explanation for why this happens. You would think centrifugal forces wouldn't allow it

That said I don't think I have ever seen 10 degrees only a few.

Posted By: roadhazard

Re: Chrome Box EIM - Does it Retard Advance? - 05/05/12 03:46 PM

Quote:

Quote:

Quote:

Dwell ddirectly affects timing,.

not if the dwell starts earlier. it can be manipulated electronically. i've checked several orange boxes, and one chrome box, to 6000 rpm- no sign of retardation (pardon the choice of words). they are all old boxes, though. i think my newest one is over ten years old. i think ballast resistor selection is important, too. iirc, there are two resistance values available? i have always used the higher resistance, and have had no ignition issues ever (aside from a ballast resistor failing at an extremely inopportune time).

In the other thread about this subject it is claimed that there was a change made to them in 2000. So if your boxes are older than that it doesn't help with this question/problem.

But thanks anyway.

So I'm safe with my chrome box from 1989

Not to derail the thread but I've never been able to get a gold box to run at all

Posted By: kilroy

Re: Chrome Box EIM - Does it Retard Advance? - 05/05/12 04:52 PM

Quote:

I have a Sun distributor machine. When I first got it I thought I wasn't using it properly or that there was something wrong with it. The timing would reach full advance at whatever rpm and then at high rpm it would loose a few degrees at max rpm. Talking with other distributor machine owners, they have found the same trends. I'd still like to hear a explanation for why this happens. You would think centrifugal forces wouldn't allow it

That said I don't think I have ever seen 10 degrees only a few.

I own a marquet dist machine and i always see a high end retard on dists also, have never figured out why. As far as box I have no idea if they retard. Sorry to high jack.

Posted By: Dunnuck Racing

Re: Chrome Box EIM - Does it Retard Advance? - 05/05/12 05:38 PM

The MP boxes don't have any intelligence in them they just pick up a signal from the distributor and use it to shut the coil on and off. The way they convert the signal is the problem.
When you get up around 4000 rpm the speed of the signal starts being a problem for the circuits to handle it.
That is the reason they show spark timing retarding. More modern systems take that signal and process it and manipulate it to do what is needed,the MP boxes are just an old design.

Keith

Posted By: rtman

Re: Chrome Box EIM - Does it Retard Advance? - 05/05/12 10:41 PM

Thanks, Keith.

So are the Chrome box circuits a similar (read: old) design that will have the same processing problem?

Posted By: Dunnuck Racing

Re: Chrome Box EIM - Does it Retard Advance? - 05/06/12 02:40 AM

RTman,
The ones I have seen do the same thing,usually around 400 rpm. Different coils and pick up coils seem to make a difference on the rpm it happens in my testing,but only by a few hundred rpm either way.
Keith

Posted By: 72demon416

Re: Chrome Box EIM - Does it Retard Advance? - 05/06/12 05:12 AM

Keith, do you have any experience with the gold boxes, to say whether they are any better or worse for dropping advance than the chrome?
Thanks,
Rick

Posted By: Dunnuck Racing

Re: Chrome Box EIM - Does it Retard Advance? - 05/06/12 02:58 PM

No,the couple of gold boxes I bought about ten years ago could not be made to work. I tried a couple of cars,and went through the wiring diagrams in the MP manual to make sure it was right.
That was when I gave up on MP boxes in my cars.

Keith

Posted By: JohnRR

Re: Chrome Box EIM - Does it Retard Advance? - 05/06/12 03:50 PM

Quote:

I have a Sun distributor machine. When I first got it I thought I wasn't using it properly or that there was something wrong with it. The timing would reach full advance at whatever rpm and then at high rpm it would loose a few degrees at max rpm. Talking with other distributor machine owners, they have found the same trends. I'd still like to hear a explanation for why this happens. You would think centrifugal forces wouldn't allow it

That said I don't think I have ever seen 10 degrees only a few.

Tom do you remember what RPM were you seeing this happen at ?